Cue Card won the William Hill King George VI Chase at the fourth time of asking for Colin Tizzard in a pulsating finish at Kempton.
The 9-2 chance has been revitalised after surgery on a trapped epiglottis and the nine-year-old had already won the Charlie Hall and Betfair Chase in the early exchanges of this season.
Willie Mullins' Vautour had looked all over the winner after taking over at the head of affairs on the second circuit from dual winner Silviniaco Conti, who disappointed and was pulled up.
Vautour was still on a hard rein with three furlongs to run as the rest were coming under pressure, none more so than the favourite Don Cossack, who to his credit was still in with a chance when he fell at the second-last.
Cue Card looked to be booked for second as Vautour pinged two out under Ruby Walsh, but his stride began to shorten, offering Cue Card a second bite.
Paddy Brennan needed a big leap on Cue Card at the final fence but he got in tight, as did Vautour, and the two gave their all on the run to the line, with Cue Card just getting the verdict.
Al Ferof finished third for the third year in succession, this time for Dan Skelton.